Electric apparatus for welding tubes.



No. 747,841. PATENTED DEC. 22. 1903. G. BAEHR. ELECTRIC APPARATUS FOR WELDING TUBES.

APPLICATION FILED JAN. 31.1902.

N0 MODEL. 3 SHEETS-SHEBT 1.

1720672 for:

' PATENTED DEC 22, 1903.

C. BAEHR.

ELECTRIC APPARATUS FOR WELDING TUBES.

APPLICATION FILED JAN 31.1902.

3 SHEETSSHEET 2.

NO MODEL.

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PATENTED DEC. 22, 1903.

G. BAEHR. ELECTRIC APPARATUS FOR WELDING TUBES.

APPLICATION FILED JAN. 31,1902.

3 SHEETSSHEET 3 NO MODEL.

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No. 747,841. Patented December 22, 1903.

UNITE cen res PATENT OFFICE,

GEORGE BAEHR, OF MCKEESPORT, PENNSYLVANIA, ASSIGNOR TO NATIONAL TUBE COMPANY, OF PITTSBURG, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

ELECTRIC APPARATUS FOR WELDING TUBES.

.EZPEGIFICATION forming part of Letters Patent No. 747,841, dated December 22, 1903.

Application filed January 81, 1902. Serial No. 92,033. (No model?! To aZZ whom it may concern: trough into tubular form, as will be readily Be it known that I, GEORGE BAEHR, a resiunderstood. The rolls 4 and 5 are mounted dent of McKeespot-t, in the county of Allein suitable bearings 7, which are supported gheny and State of Pennsylvania, have inon the housings 9 and which are adjusted to- 5 ventedanewand usefulItnprovementin Elecward and from each other by means of the tric Apparatus for Welding Tubes; and I do screws 8. The rolls 6 are mounted in suithereby declare the following to be a full, clear, able bearings 10, which are suitably su pportand exact description thereof. ed on the cross-beams 11, secured to the hous- My invention relates to an electric tubeings 9. Suitable screws or bolts 12 are proto welding machine; and its object is to provide Vided for adjusting these rolls horizontally on a machine for this purpose in which the weldsaid cross-beams. Both set of bending-rolls ing apparatus is readily adjustable to adapt may revolve idly, the plate being drawn or it to tubes of various sizes. otherwise suitably fed therethrough; but I A further object of my invention is to proprefer to drive the rolls positively, so that [5 vide a machine which will progressively bend they will feed the plate forward. Any cona flat plate into tubular form and progresvenient mechanism for positivelydriving the sively weld the joint thereof electrically. rolls may be employed; but I prefer to em- A further object of my invention is to imploy electric motors for this purpose. A sinprove a machine of this kind in details of gle electric motor could be used for driving 20 construction, as Will hereinafter appear. both pairs of rolls by means of suitable in- In the accompanying drawings, Figure 1 is a tel-mediate gearing; but I prefer to use a sepplan view of my improved machine, one side al'ate motor for driving each paitof rolls and of the welding apparatus being omitted. Fig. have therefore shown a motor 13 for driving 2 is a similar view enlarged of the main porthe rolls 4. and 5 and a motor 14: for driving 25 tion of said machine. Fig. 3 is a central ionthe rolls 6. The motor 13 has its armaturegitudinal vertical section through bending shaft provided with the worm 15, which and welding mechanism. Fig. i is a transmeshes with the worm-wheel 16 on the upper verse sectional View through the welding end of a shaft 17, to which shaft are secured mechanism. Fig. 5is a side View of the same. two worms, (not shown,) one right hand and 0 Fig. 6 is a detail and face view of the plani the otherleft hand, which mesh, respectively, etary welding roll or wheel. Fig. 7 is a set;- with corresponding worm-wheels 18 on the tioual detail of-the tubesupport, and Fig. 8 shafts of each of the rolls i and 5. The mois a front view of one of the slides which suptor 1% has its armature-shaft provided with port the welding-rolls. a worm 19, which meshes with a worm-wheel 55 My machine in its entirety comprises the 20 on the horizontal shaft 21, said shaft being plate-bendingmechanism 1, the tube-welding provided with two worms 22, one right hand mechanism 2, and the feeding or drawing and the other left hand, which mesh with the mechanism worm-wheels 23 on the shafts of the rolls 6. The plate-bending mechanism may be of The motors l3 and 1% will be supported on 40 any suitable construction for progressively the frame in any suitable position, and any bending a flat plate into tubular form. A vasuitable intermediate gearing may be used to riety of such bending mechanisms are well connect them to the rolls 4, 5, and 6, that knownin the art, and they may all be adapted shown being only one form of many adapted for the purposes of my machine. In Inedrawfor this purpose. By using separate motors 5 ings I have shown such mechanism composed for driving the two sets of bending-rolls the 5 of two sets of rolls, the first set com prising gearing can be much simplified, thus reducthe concave roll 4 and the convex roll 5 and mg friction, and an elastic or yielding pull on the second set comprising two groored rolls the plate may be secured by giving the motor 0. The first set of rolls bend the plate into 1% a slightly higher speed than the motor 13. l 50 trough form and the second set bend the To insure the bending of the plate into per- 1m vance of the welding mechanism.

icct tubular form, it may be desirable to use an internal mandrel or bulb,and I have shown for this purpose a mandrel 24, secured to a cone 25, depending from a plate 26, integral with or suitably secured tothecross-beam 11.

The mandrel or bulb, however, may be supanism 2 and may even force the same through said welding mechanism without the aid of any other feeding mechanism; but as an additional means for feeding the tube forward ll prefer, for abundant caution, to use some form of pulling or feeding mechanism in ad- A variety of mechanisms for this purpose may be used, and in the drawings I have shown an ordinary draw bench 29, provided with the sprocket or like wheels 30, over which passes an ordinary d raw-chain 31. Any convenient form of grip and buggy may be used, and in the drawings 1 have shown a grip diagrammatically at 32, the same being mounted on a buggy 33, having a hooked arm 34, which is adapted to catch onto the draw-chain in a manner well understood in the art. The draw-chain may be driven by any suitable mechanism, and I have shown for this purpose the electric motor 35, which may be geared to the rear sprocket-wheel by means of any suitable intermediate gearing. This drawing mechanism may, if desired, draw the plate not only through the welding mechanism, but also through the bending-rolls, so that the latter may run idly. In that event, however, a grip would have to be employed which can pass through both the welding and the bending mechanisms. 1 prefer,theret'ore, to positively drive the bending-rolls and use the chain 31 only as an additional means to insure the positive feeding of the plate and tube through the apparatus. The motor 35 is preferably run at a slightly higher speed than the motorl4, thereby securing an elastic or yielding pull on the plate and tube as they pass through the bending and Welding mechanisms.

The welding apparatus 2 comprises two similar mechanisms located on the opposite sides of the tube. These mechanisms are each suitably insulated from the bed-plate 36, as by a non-conducting plate 37. Each mechanism comprises a base 38, provided with a suitable transverse guideway, in which moves the slide-post 39, the latter being moved toward and from the center of the machine by any 7 suitable means, such as an ordinary screw and hand wheel 40, operating in the \VGlblKIlOW'Q manner of moving slide-rests in lathes. This slide-post 39 is provided on one side with suitable guides for receiving a vertically movable slide 42, the same being moved by means of a screw and hand wheel 43, as will be readily understood. Pivoted to the slide 42, as at 45, is a lever 46, which carries at its inner end a journal-bearing 47 for a pressure-roller 48. The outer end of the lever is provided with a clam p-bolt 49, which moves in a curved slot in the slide 42, the arc of said slot being struck about the pivot 45 as a center. By this means the lever 46 can be swung about the pivotal point 45 and locked in any desired position by means of the bolt 49. Pivoted at its outer end to the outer end of the lever 46 is another lever 51, which carries at its inner end cross-head 52, provided with suitable journal-bearings for a pair of guide-rollers 54. The pressure-roller 4S and the guide-rollers 54 bear on the inner periphery of the planetary current conducting and welding wheel or ring 55, the faces of the pressure and guide rollers being grooved, as shown, or otherwise shaped and the inner periphery of the ring or wheel being shaped to correspond to the faces of the rollers, so that said ring or wheel is supported and guided on said rollers. Means must be provided for pressing the guide-rollers 54 and pressure-rollers 48 against the inner periphery of the planetary ring 55, so as to prevent the latter from dropping off said rollers. .As a suitable means for this purpose I have shown a guide-post 56 secured to the lever 46 and passing through an opening in the lever 51, and interposed between said levers is a compression-spring 5'7, which tends to force the lever 51 away from the lever 46, thereby holding the rollers 48 and 54 firmly against the inner periphery of the planetary ring 55. The planetary ring 55 serves as the means for conducting the electric current to the tube to be welded, and in order to getagood contact between the tube and Ihe condncting'ring the latter has its ouler periphery concaved slightly to conform to the contour of the tube. It follows that for different sized tubes conducting rings or wheels having, different degrees of concavity must be used. These rings or wheels therefore are made interchangeable, and the means above described for mounting them permits of the easy and rapid removal of such ring and its replacement by another. For this purpose it is only necessary to move the guide-rollers 54 against the tension of the spring 57 sufficiently far to release the planetary ring 55 from said rollers, when another ring having a periphery of diiferent concavity can be put in place. It is not necessary to use two guiderollers 54, as a single one would serve the purpose; but the pair hold the ring 55 steadier. Neither is it necessary that the rollers 48 and 54 be grooved and the ring 55 be formed with a projection, as shown, as these parts may be reversed and may be made of any other conl urthermore, instead tour than that shown.

ICC

of using a spring for forcing the levers apart positive meanssuch, for instance, as an adjusting screw or bolt, as shown in Fig. 6-may be used for this purpose.

The welding mechanism on the two sides of the machine, as above stated, are identical, so that the two current-conducting devices 55 bear, respectively, on the opposite sides of the tube-joint, as shown, one of said conducting devices being connected to one pole of the source of electricity and the other to the opposite pole, so that the current will pass across the tube-joint and heat the edges of the bentup plate. The current can be conducted to the rings 55 in any desired way, and I have shown for this purpose the brushes 60. Two pairs of such brushes are shown for each ring 55, each pair being mounted upon a bolt 61, which is secured in the outer end of the arm 62, projecting from the side of the lever 46. The terminals may be connected directly to the brush-as, for instance, by the bindingscrews 64or they may be connected to the bolts 61, or, indeed, to any part of the devices supporting the current-conducting rings 55. It is desirable, however, to connect the same as close to the brushes as possible in order to avoid passing the current across the joint in the mechanism and especially through lubricated bearings which are of high resistance.

To prevent the tube from turning so that the joint will not be between the conductingrings 55, I provide a suitable guide-blade 65, which is adapted to project into the open joint of the tube in front of the welding mechanism, said guideblade being supported on the inner end of an arm 66, adjustably secured to the front of one of the slide-posts 39.

To support the tube and hold it against the current-conducting devices 55,1 employ a pair of rollers 67, which bear upwardly upon the lower outer side of the tube, as shown, and resultantly administer pressure for forcing the abutting edges of the tube against each other, so that when heated by the electric current the said edges will weld fast to each other.

In order to prevent the current passing through the pressure and supporting rollers 67 instead of passing across the tube-joint, it is desirable that these rollers occupy as small a portion of the tube circumference as possible, so as to leave wide air-gaps between themselves and the current-conducting devices. I have therefore shovn the rollers as comparatively narrow. As a further aid,however, to prevent leakage of current around the tube and also to prevent. grounding the current through the base of the machinei form these rollers of non-conducting materialsuch, for instance, as layers of fiber the construction being clearly shown in the drawings. Said rollers 67 mounted on inclined studs 68, secured in the upper end of a guide-post 69, which is vertically movable in a base 70 and is normally pressed upwardly by a spring 71, interposed between the head of said guide-post and a shoulder 72 on the post 73. This post is provided at its lower end with screw-th reads, as shown, so that by turning it in one direction or t he other the height of the shoulder 72 may be varied, thereby varying the position of the rollers 67 with reference to the axis of the tube. The post 73 is provided at its upper end with the extension 7%,which projects through the head of the guide post (39 and which has at its upper end a nut or other suitable stop 75 for limiting the upward movement of the guidepost 69 under the tension of the spring 71. Suitable means are provided for preventing the rotation or turning of the guide-post 69 in the base 70such, for instance, as the setscrew 7o, projecting through the base into a vertical slot 77 in the guide-post.

The operation of the machine will be understood from the foregoing description. Sn ffice it to say that after the current has been led to the conducting-rings 55 and all of the motors have been started the end of a plate is fed to the rolls 4 and 5, which grip the same, bend it up into trough shape, and feed it forward to the rolls 6, which complete the bending of the plate into tubular form and feed the same forward into the welding mechanism. The guide-blade enters the joint of the tube and prevents the same from turning as it passes through the welding mechanism. The tube is supported by the spring-pressed rollers 67 and pressed against the conducting rings or wheels 55, which bear on opposite sides of the joint. The current from one of the conducting devices 55 passes across the joint of the tube to the other of said conducting devices, thereby heating the abutting edges, which under the resultant influence of the pressure of the rollers 67 are caused to weld together. The forward end of the tube is caught by the grip 32, and by means of the chain 31 the tube is drawn through the welding and bending mechanism at the desired rate of speed, the bending of tne plate into tubular form and the welding of the same taking place continuously and progressively.

To adapt the welding mechanism to tubes of different sizes, the slide-posts 39 will be moved inward or outward, as necessary, and the siides e2 raised or lowered correspondingly. The cmitact-rings 55 will be replaced by others having the necessary concavity to fit the contour of the tube, and the levers 46 will be swung around their pivots 45 until the face of the contact-rings will bear squarely against the outer surface of the tube. In this way a good contact between the rings and the tube is assured, thereby permitting the passage of a current of large volume. In the operation of the welding apparatus the rings 55 revolve upon and around the rollers 48 and 5%, so that this mechanism may be said to be of a planetary type. The current connections to the rings 55 are made through the brushes, as described, so that the current need not traverse any joints in the mechanism, and especially need not pass through lubricated bearings which are of high resistance.

What I claim as my invention, and desire to secure by Letters Patent, is

1. In apparatus for welding pipes or tubes electrically, the combination of suitable supporting and holding devices for the tube, and two current-conducting devices respectively connected with opposite poles and adapted to bear on opposite sides of the tube-joint, said devices comprising supports and removable and interchangeable planetary conducting-rings rotatably mounted thereon.

2. In apparatus for welding pipes ortubes electrically, the combination of suitable supporting and holding devices for the tube, and electric-current-conducting devices adapted to bear on opposite sides of the tube-joint, said devices com prising suitable supporting rollers and planetary conducting-rings rotatably mounted thereon.

3. In apparatus for Welding pipes or tubes electrically, the combination of suitable supporting and holding devices for the tube, and two current-conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprising a planetary conducting-ring, two or more su pporting-rollers therefor, and means for holding said rollers against the inner periphery of the planetary ring.

4. In apparatus for welding pipes or tubes electrically, the combination of suitable supporting and holding devices for the tube,and two current-conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprising a planetary conducting-ring, two or more supporting-rollers adapted to bear on the inner periphery of said ring, levers on which said rollers are mounted, and means for forcing said levers apart whereby the rollers are held against the inner periphery of the ring.

5. In apparatus for welding tubes or pipes electrically, the combination of suitable supporting and holding devices for the tube,and two current-conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprising a planetary conducting-ring, rollers adapted to bear on the inner periphery thereof, a support for one of said rollers, a lever pivoted to said support and serving as a support for another of said rollers, and a spring between the support and lever for forcing the rollers apart and holding them against the inner periphery of the planetary ring.

6. In apparatus for welding pipes or tubes electrically, the combination of suitable supporting and holding devices for the tube, and two electric-current-conducting devices adapted to bear on opposite sides of the tubejoint, each of said devices comprising a planetary conducting ring, supporting rollers re /s41 therefor adapted to bear on theinner periphery thereof, a pivoted lever on which one of said rollers is mounted, asupporting-arm for the other of said rollers, said arm being pivoted to said lever, and means for forcing said arm away from said lever to hold the rollers against the inner periphery of the planetary ring.

7. In apparatus for welding pipes or tubes electrically, the combination of suitable supporting and holding devices for the tube,and two current-conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprising a planetary conducting-ring, and suitable supporting-rollers adapted to bear on the inner periphery of said ring, said rollers and said ring being provided with interlocking meeting faces.

8. In apparatus for welding pipes or tubes electrically, the combination with suitable holding and supporting devices for the tube, of two current'conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprisin a planetary conducting-ring, two or more supporting-rollers therefor, means for holding said rollers against the inner periphery of the ring, and means for adjusting said supporting-rollers toward and from the tube to be welded.

9. In apparatus for welding pipes or tubes electrically, the combination with suitable holding and supporting devices for the tube, of two electric-current-conducting devices adapted to bear on opposite sides of the tubejoint, each of said devices comprising a planetary conducting-ring, two or more supporting-rollers therefor, means for holding said rollers against the innerperiphery of the ring, a pivoted lever on which said rollersare mounted, and means for adjusting said lever about its pivot.

10. In apparatus for welding pipes or tubes electrically, the combination with suitable supporting and holding devices for the tube, of two electric-current-conducting devices adapted to bear on opposite edge portions of the tube-joint, said devices each comprising a planetary conducting-ring, two or more so pporting-rollers therefor, means for holding said rollers against the inner periphery of the ring, and means for adjusting said supporting-rollers both horizontally and vertically.

11. In apparatus for welding pipes or tubes electrically, the combination with suitable holding and supporting devices for the tube, of two electric-current-conducting devices adapted to bear on opposite sides of the tubejoint, said devices each comprising a planetary conducting-ring, two or more supporting-rollers therefor, pivoted levers on which said rollers are mounted, means for adjusting said levers about their pivots, and means for adjusting the lever-supports both horizontally and vertically.

12. In apparatus for welding pipes or tubes electrically, the combination with means for IIO feeding the tube longitudinally, of two electric-current-conducting devices adapted to bear on opposite sides of the tube-joint, sup porting devices for the tube located opposite said current-conducting devices, and means for yieldingly holding the same against the tube.

13. In apparatus for welding pipes or tubes electrically, the combination with means for feeding the tube longitudinally, of two electric-current-conducting devices adapted to bear on opposite sides of the tube-joint, adjustable supports for said devices, two rollers adapted to support the tube opposite said ourrent-conducting devices,-and means for yieldingly holding the same against the tube.

14. In apparatus for welding pipes or tubes electrically, the combination with springpressed supporting-rollers for the tube, of two current-conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprising a planetary conducting' ring, supporting-rollers on which they are mounted, a support for said rollers and means for adjusting said support toward and from the tube to be welded.

15. In apparatus for welding pipes or tubes electrically, the combination with spring pressed supporting-rollers for the tube, of two current-conducting devices adapted to bear on opposite sides of the tube-joint, each of said devices comprising a'planetary conducting-ring, supporting-rollers therefor, a pivoted lever on which said rollers are mounted, and means for adjusting said lever about its pivot.

16. In apparatus for welding pipes or tubes electrically, the combination with springpressed supporting-rollers for the tube, of two current-conducting devices adapted to bear on opposite sides of the tube-joint, said devices comprising removable and interchangeable planetary conducting rings or Wheels, pivoted levers on which they are rotatably mounted, and means for adjusting said levers about their pivots.

17. In apparatus for welding pipes or tubes electrically, the combination of two currentconducting devices adapted to bear against opposite sides of the tube-joint, of two rolls adapted to support the tube, an adjustable support for said rolls, and a spring between said support and the rolls.

18. In apparatus for welding pipes or tubes electrically, the combination with two electric-current-conducting devices adapted to bear on opposite sides of the tube-joint, said devices comprising removable and interchangeable rings or wheels, adjustable supports for the same, supporting-rollers for the tube, and an adjustable and yielding sup port for said rollers.

19. In apparatus for welding pipes or tubes electrically, the combination with positivelydriven rolls for progressively bending a flat plate into tubular form, means for holding the same in such form and pressing the abutting edges against each other, currentconducting devices adapted to bear on opposite sides of the tube-joint and thus cause a current 0t electricity to flow across said joint and heat the edges of the plate, whereby said abutting edges are caused to weld together, and means for feeding the plate through the bending and welding devices.

20. In apparatus for welding pipes or tubes electrically, the combination with a pair of concave and convex rolls, of a pair of grooved rolls, heating and welding apparatus adjacent to said rolls, a drawing device, and independent electric motors for driving each of said pairs of rolls and said drawing device.

In testimony whereof I, the said GEORGE BAEI-IR, have hereunto set my hand.

GEORGE BAEHR.

Witnesses:

J. A. CAUGI-IEY, W, H. SIGNET, Jr. 

